From the ArcaMax Publishing, Vocabulary Newsletter:
http://www.arcamax.com/news/vocabulary/s-343406-772058
autodidact \aw-toh-DY-dakt\ (noun) - One who is self-taught.
"I'm an autodidact and a good one, because I'll kick my own (butt) if
I don't learn, which is a sight to see with this leg brace." -- Dean
Koontz, 'One Door Away from Heaven'
Autodidact is from Greek autodidaktos, "self-taught," from auto-,
"self" + didaktos, "taught," from didaskein, "to teach."